The present invention is related to a grinding apparatus, and more particularly to a grinder having a press button. By means of pressing the press button, the rotary shaft of the grinder can be seized for replacement of the grinding disc. The press button is prevented from being mis-touched by a user so as to avoid damage of the grinder.
A conventional grinder such as a pneumatic grinder or an electric grinder is equipped with a grinding disc at bottom end for grinding a work piece.
When replacing the grinding disc, a user needs to chuck the rotary shaft with one wrench and wrench the nut at bottom end of the rotary shaft with another wrench. After the nut is untightened, the original grinding disc can be taken off and a new grinding disc can be fitted on the rotary shaft. Then the nut is retightened to fix the new grinding disc.
It is inconvenient to operate two wrenches at the same time. In order to solve this problem, an improved grinder has been developed. A chucking press button is disposed on the housing of the grinder. When pressed, the press button is moved into the interior of the grinder to chuck the rotary shaft. Under such circumstance, when replacing the grinding disc, a user only needs to wrench the nut with one wrench.
However, the above chucking press button is often incautiously mis-touched in operation. Under such circumstance, the rotary shaft will be suddenly seized by the press button. This will lead to damage of the grinder.